If you tell me the of your NCU or if you're looking for a specific update (like Update 12), I can point you to the exact document ID for your setup.

The download began.

Verification and acquisition of the Toolbox typically occur through official Siemens channels. Official Access

To ensure a installation, you should download the software only from the Siemens Industry Online Support (SIOS) portal.

: Run the setup; it will allow you to select components for "SINUMERIK 840D sl" and "SINUMERIK ONE" if using the unified package. Project Setup